Messages in this thread | | | Date | Tue, 17 Jul 2012 15:24:44 -0700 | From | Tejun Heo <> | Subject | Re: [REGRESSION] [PATCH] block: uninitialized ioc->nr_tasks triggers WARN_ON |
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Hello, Olof.
On Tue, Jul 17, 2012 at 02:36:43PM -0700, Olof Johansson wrote: > It seems like the init of ioc->nr_tasks was removed in that patch, > so it starts out at 0 instead of 1. > > Tejun, is the right thing here to add back the init, or should something else > be done? > > The below patch removes the warning, but I haven't done any more extensive > testing on it. > > > Signed-off-by: Olof Johansson <olof@lixom.net>
Right, the patch shouldn't have replaced the init.
Acked-by: Tejun Heo <tj@kernel.org>
Fortunately, the effect of the bug is limited. ioc->nr_tasks only used to veto block cgroup migration if a task has ioc which is shared by multiple tasks. Currently, the only known program using CLONE_IO is dump and even if somebody migrates some threads of a single dump instance to a different block cgroup, the result won't be catastrophic although block cgroup policies would become ambiguous. IMHO, it should be okay to route this through -stable after 3.5. Jens?
Thanks.
-- tejun
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